1. Field of the Invention
This invention generally relates to electrical signal connector interfaces and, more particularly, to a system and method for using a single electrical connector to multiplex digital and analog signals to and from a device.
2. Description of the Related Art
Connectors are used to interface devices for the purpose of communicating signals or power. These signals can include digital data signals and analog signals. The following discussion is directed to audio analog signals. However, the discussion applies to other types of analog signals as well. Typically, connectors are configured to accept one particular type of connector interface, for example, a jack. As is well known, there are a large variety of cable types and associated connector interfaces. Typically, each particular type of connector interface is configured to handle only one specific type of signal. For example, wireless communications devices may use a connector accepting a four-line jack for a headset. The lines from the jack supply an audio input signal from a microphone in the headset, accept an audio output signal for a mono speaker in the headset or audio output signals for stereo speakers in the headset, and ground the headset to the device. The connector for the headset jack does not accept other types of cable connectors. For example, a separate connector, incompatible with the headset jack, is used to send and receive digital signals through an alternate port. In addition, separate sub-systems are typically used in a wireless communications device to supply and accept different types of signals to and from a connector in the device. The sub-systems may have different operating parameters and sensitivities and are typically not designed to handle other types of signals. For example, voltages associated with an audio signal could damage digital data signal circuits. Therefore, using separate, incompatible connectors in a wireless device serves the purpose of protecting circuitry in the device from the inadvertent application of potentially damaging signals to the circuitry. For example, as noted above, a user cannot inadvertently insert the headset jack into a digital data connector.
Therefore, it is known to use separate connectors to accept and supply digital and analog signals. However, there are disadvantages associated with the use of separate connectors for different signal types. A wireless communications device is used as an example to illustrate these disadvantages. However, it should be appreciated that these disadvantages apply to other portable devices and non-portable devices as well. Advances in technology and manufacturing techniques permit wireless communications devices to be made increasingly smaller, which in turn, creates a need to reduce the space required for components in the devices by reducing the number and/or size of the components.
Unfortunately, providing separate connectors increases the component parts count in a wireless device. The subsequent increase in space usage can limit the size to which a wireless device can be reduced, or can limit space available in the wireless device for other components. Increasing the parts count for a wireless device also adds to the cost of producing the wireless device. Since general reliability decreases as parts count in a wireless device increases, increasing the parts count by using separate connectors also decreases the reliability of the wireless device.
It would be advantageous if the number of connectors used in a device to accept and supply digital and analog communication signals could be reduced.